Effects of hollow carbon nanospheres on combustion performance of Al/Fe2O3-based nanothermite sticks

• Published in: Journal of alloys and compounds Vol. 918; p. 165684
• Main Authors: Yang, Haifeng, Xu, Chuanhao, Man, Shuaishuai, Bao, Hebin, Xie, Yuting, Li, Xiaodong, Yang, Guangcheng, Qiao, Zhiqiang, Li, Xueming
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.10.2022; Elsevier BV
• Subjects: Carbon; Combustion release rate; Combustion temperature; Convective heat transfer; Design optimization; Direct-writing; Energy absorption; Heat transmission; Hollow Carbon nanospheres; Ignition; Ignition Threshold; Nanospheres; Porosity; Thermite stick; Ignition Threshold; Hollow Carbon nanospheres; Thermite stick; Combustion release rate; Direct-writing
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.165684

Effects of hollow carbon nanospheres on the combustion behavior of Al/Fe2O3-based thermite sticks are studied in this work. The results from laser ignition experiments confirm that the presence of hollow carbon nanospheres not only can reduce the ignition threshold because of the excellent laser energy absorption capacity, but also play a positive role in heightening the heat transfer efficiency by introducing pores and increasing heat-flow output during the combustion process. The video snapshots indicate that the combustion propagation stages, including ignition, acceleration, and steady combustion, all improved significantly with the suitable inclusion of hollow carbon nanospheres. The modified composites containing 4 wt% hollow carbon nanospheres exhibit a minimum ignition threshold (28 mJ), shorter acceleration duration (76 ms), higher combustion rate (10.10 cm/s) and steady combustion temperature (~2850 K). Furthermore, it exhibits a remarkable enhancement in energy release (537.36 J/g) and pressure output (0.91 Mpa), which are 1.67 and 1.34 times than that of pristine thermite sticks, respectively. Overall, this work demonstrates that the high porosity structure and heat-flow release of thermite sticks facilitate convective heat transfer and eventually improve the combustion behavior, which can provide some reference in the design and optimization of microstructure and composition in micro-energetic devices. [Display omitted] •Hollow carbon nanospheres are first employed into Al/Fe2O3-based thermite sticks as additives.•Effects of the hollow carbon nanospheres on combustion behavior of thermite sticks are studied.•The modified thermite sticks exhibit the lower ignition threshold.•The introduction of gas-producing additives is beneficial to improve heat transfer capacity.•The modified thermite sticks show the higher burning rate, energy and pressure release, and combustion zone temperature.